Amp Tech Thread / Ask a tech Q

[grimniggzy]

Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)

I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel

Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail

http://www.carvinguitars.com/products/single.php?product=PS12-8

Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories

Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370

The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.

Many thanks in advance.

nothing special in wiring. ohms are ohms. i would worry abou thte open back cab though.

Noted. I'll probably opt for the open/closed option its only $25 extra.

So the first diagram on \/ this \/ page would be me right?
http://www.colomar.com/Shavano/2x12wiring.html

[justinhedrick]

Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)

I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel

Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail

http://www.carvinguitars.com/products/single.php?product=PS12-8

Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories

Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370

The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.

Many thanks in advance.

nothing special in wiring. ohms are ohms. i would worry abou thte open back cab though.

Noted. I'll probably opt for the open/closed option its only $25 extra.

So the first diagram on \/ this \/ page would be me right?
http://www.colomar.com/Shavano/2x12wiring.html

yepps.

[grimniggzy]

mucho appreciatto mi amigo

[grimniggzy]

now all i need is the money, uggh

[justinhedrick]

now all i need is the money, uggh

i know what you mean! i just got a bonus check at work today, and it is already spent paying off the wife's credit card.

i could have bought an AWESOME cab with it.

[grimniggzy]

My bonus this year went straight into savings. Dis nigga needs a car, don't even know why I'm looking at cabs.

[Hemisaurus]

I'm seeing 212's for $100 and under at the musicgoround, sure they ain't as pretty as the one you want, but I bet they make noise, and they look deeper than the one you had linked, better bass response



http://musicgoround.com/search.aspx?q=212+cab&cid=8&scid=0&sid=0&d=10&c=10&ob=6&p=2

[grimniggzy]

Yeah, I should look into used stuff before I make a purchase.

[justinhedrick]

Yeah, I should look into used stuff before I make a purchase.

good idea. plus, on that music go round website that hemi linked to there is a 2x12 "steel sound" bass cab for $100 in louisville, ky.

[VOLVO)))]

I'd be wary putting the 370 to 2 12's... it's kinda scary with 15s...

[Hemisaurus]

Go back to school, and write out 100 times It's not the size, it's the handling.

I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.

I still like the 15"s though, for spreading the power through four of them

[VOLVO)))]

Go back to school, and write out 100 times It's not the size, it's the handling.

I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.

I still like the 15"s though, for spreading the power through four of them

yeah yeah yeah, but it still feels wonky to me putting so much power to two 12s...

[Ayek]

I've always thought it's weird using 10" speakers on bass and 12"s on guitar, so there you go.

[Hemisaurus]

Me too, i think Ampeg started it, and I imagine it was a compromise so that they could fit 8 drivers into a reasonably sized cabinet. I think when the SVT first arrived, they needed all 8 drivers to handle 300W, just a theory.

I still think 15"s are the way to go, personally.

[grimniggzy]

Go back to school, and write out 100 times It's not the size, it's the handling.

I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.

I still like the 15"s though, for spreading the power through four of them

yeah yeah yeah, but it still feels wonky to me putting so much power to two 12s...

Yeah, I'd probably just use the Beta or C.Bass to run a 2X12. The 370 through 15's is mighty impressive.

[Mr. Foxen]

Me too, i think Ampeg started it, and I imagine it was a compromise so that they could fit 8 drivers into a reasonably sized cabinet. I think when the SVT first arrived, they needed all 8 drivers to handle 300W, just a theory.

I still think 15"s are the way to go, personally.

Needed 16, the SVT was supposed to run two cabs for full tilt. They were basically guitar drivers anyway. Speaker diameter hasn't go much bearing on things, especially if you have multiples in a box.

[Ayek]

Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.

[moose23]

Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.

One word "slap". That's the style of bass playing and what bass players who use tweeters need. 

[VOLVO)))]

Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.

One word "slap". That's the style of bass playing and what bass players who use tweeters need. 

Unless you're that guy from Korn -shudder-

[moose23]

Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.

One word "slap". That's the style of bass playing and what bass players who use tweeters need. 

Unless you're that guy from Korn -shudder-

He needs a slap too.

[SoupKitchen]

So really nerdy amp question here. I want to build an amp with parallel channels, like a tweed Bassman or a Marshall 1987/1959, with the channels jumpered and each channel voiced differently. If I want to blend those channels, can I just put them on a 1Meg dual-ganged linear pot, and where would said pot go? If I place the pot before the coupling cap(s), I get DC on the pot and a scratchy pot. If I put the pot after the caps (where the volume pots traditionally go), would the coupling caps create phase problems? What if they're different sizes (say .022 and .068)? I could just use a post-phase inverter master to control volume, rather than individual channel volumes. Thanks!

[dunwichamps]

dont worry about phase problems. not important.

[mortlock]

why the fuck is something as simple as getting a good 9v neg center adaptor so complicated..theres a million different sizes..wattages, amps..wtf.

i dont understand how there is not some sort of industry standard going on here..

[VOLVO)))]

One spot.

[Hemisaurus]

Things to look for are current capacity, and is it regulated.

Current capacity is obvious, do you have enough current to power all the pedals?

Regulation, is where the voltage is kept at 9 volts, no matter what the current drawn (unless you go over the rating). A lot of pedals are unregulated, they may be  9V at 500mA but if your pedal only draws 200mA, they may be up at 13 or 14 volts This can harm sensitive pedals, but is harmless to most.